HERE IS WHAT HAPPENED. Yesterday, I discovered the green connector for CEL testing has been plugged in forever. i unplugged it, and proceeded to do what I know, in order to read the check engine light. The oxygen monitor showed codes 21(coolant temp sensor), 24(idle air control valve or circuit) and 34(EGR solenoid or circuit). It got dark, so I went inside and proceeded to look online for a replacement IACV gasket, so I can clean it. I also looked at an EGR solenoid and planned on cleaning the EGR today. When I went to start my car this morning, it fired but died immediately, and I knew something was wrong. One more start and die, and without pumping the throttle or having it wide open, the car just cranked and didnt fire. What the heck? So I read the codes again, and nothing had changed. As far as I know the only thing I did was make a red light blink, so i'm a little confused. Is it possible that the car is acting up because the ECU "didnt know" about the bad egr and iacv until i put it in test mode? before having gone inside last night i started the car, and it RAN FINE. Again, what the heck? Does anyone have any ideas? car has always had idle issues, and at one point an ignition coil that arced to the negative ground. ask me questions and i will answer, but so far, thats what i got.

 

Thank you guys in advance. -walker

i dont suppose you loosened the intake boot or anything under the hood did you??

IN test mode it was defaulting to run rich.

 

With a bad coolant temp sensor....it will be hard to start or run well.  replace the CTS.  IAC and EGR codes are no big deal.